環境因子對 Gracilaria tenuistipitata 生成前列腺素 E2 的影響   全文下載

Factors Affecting PGE2 Production in Seaweed Gracilaria tenuistipitata

菊花心龍鬚菜Gracilaria tenuistipitata 是一種可食性紅藻，其常被利用作為九孔之餌料與食品原料（如洋菜之提煉），在台灣龍鬚菜養殖以菊花心龍鬚菜為主要品種。本篇報告之主題為研究環境因子對菊花心龍鬚菜G. tenuistipitata 生成前列腺素e2（PGe2）的影響，實驗結果發現，G.tenuistipitata 由鹽度2% 的海水分別移至鹽度1% 及3% 的海水中12 hr 後，前列腺素e2 含量分別增加了2 倍及47%，低溫及照光度的改變也會促進G. tenuistipitata 中前列腺素e2 的生成，此外離水2 及4 hr 後，G. tenuistipitata中前列腺素e2 的含量分別增加了25% 及31%，但浸漬於淡水中會使前列腺素e2 的含量漸漸減少，當海水中銅及鋅離子的濃度分別為3 及50 mg/L 時會抑制前列腺素e2 的生成，此外當海水中鎂離子的濃度為2,025 mg/L 時G. tenuistipitata 中前列腺素e2 的含量減少20%，但當海水中鈣離子的濃度為600 mg/L 時前列腺素e2 的含量增加了59%。顯示環境因子會顯著影響G. tenuistipitata 生成前列腺素e2，推測前列腺素可能參與了某些代謝過程，幫助藻體在不利的生長環境中生存，因此建議養殖業者在龍鬚菜養殖期間減少其生長環境的變動，以避免龍鬚菜中前列腺素e2 含量增加，此外消費者也應避免生食龍鬚菜，要先經烹調後再食用，因加熱可以破壞並減少前列腺素e2 的含量，確保其食用安全。"

Gracilaria tenuistipitata is an edible red alga and can be utilized as feed for small abalone and foodstuff (ex. agar extract). It is the major species of Gracilaria that is commonly cultivated and consumed in Taiwan. Effects of environmental factors on prostaglandin E2 (PGE2) production in the seaweed G. tenuistipitata were investigated in this study. PGE2 amount increased nearly 2-fold and 47% when the seaweed was exposed to two ways of fluctuation of seawater salinity from 2% to 1% and 3% for 12 hr, respectively. The stresses of low temperature and irradiance promoted the seaweed to produce PGE2. When the seaweeds were exposed to air for 2 hr and 4 hr, the PGE2 levels were elevated by 25% and 31%, respectively. When the seaweed was soaked in freshwater, PGE2 amount gradually decreased. Cu2+ and Zn2+ inhibited PGE2 production at the concentrations of 3 and 50 mg/L, respectively. Mg2+ slightly inhibited PGE2 production about 20% at 2,025 mg/L, while Ca2+ boosted PGE2 production about 59% at 600 mg/L. Hence, environmental factors significantly affect the PGE2 production in the seaweed G. tenuistipitata. Prostaglandins might be associated with processes permitting the algae tissue to survive in unfavorable conditions. To lower the amount of PGE2 in the seaweed and ensure the food safety, it is suggested to minimize the variation of growth condition to avoid PGE2 increase in the seaweed during cultivation period. In addition, consumers should avoid eating raw seaweed since PGE2 could be destroyed by heating